intro to med Flashcards
what is a drug
pharmacologically active ingredients
API active pharmaceutical ingredient
what is a medicine
means of administrating a drug in a safe and efficient manner - contains drug and excipients
what is an excipients
inactive substance used as a carrier for the active ingredients of a medication
name the routes of administration
oral,
rectal,
topical,
parenteral,
pulmonary routes,
nasal,
ocular (eyes),
otic (ears)
problems associated with different administration
GI -pH,gastric emptying,enzymes,bile
respiratory tract - mucociliary
rectal- poor retention of small dosage, small SA compare to GI tract.
A good medicine has (4 things)
dose uniformity - accurate dose
patient acceptability - pleasant to use
stability long shelf life
directions of use
name the 3 types of powder
effervescent powders - contain acid and carbonate
dusting powders - talc
powders for syrup - for kids and when formulation are unstable as a solution or a suspension.
what is granulation
approach to prevent segregation by forming granules which contain correct ratio of ingredients.
ADV of powders
-faster dissolution rate
-more stable than liquid
- convenient for high dose drugs
versatile dosage form - can be customised.
DISADVANTAGES of powders
- not suitable for drugs which are inactivated in the stomach
- stability challanges - Difficult to protect hygroscopic and deliquescent substances
- less convenient - carry and prepare
what is a tablet
formed by compression of powder or graules.
ADVANTAGES of tablets
- accurate dosing
-long shelf life
-controlled release options.
-taste masking
DISADVANTAGE of tablets
- difficulty swallowing
-delayed onset - may take longer to absorb compared to liquids and powders.
-inactivation in stomach acid.
how does a tablet press work
- A die is filled with powder/granules
- mechanical force is applied between upper and lower punches
- Tablet is ejected.
what is dissolution and why is it important
e process by which a substance (often a solid) dissolves in a solvent to form a solution.
sold substance need to be dissolved in order to be absorbed into the GI
what is the dissolution rate
rate at which drug particles become individually dispersed within a solvent
noyes -whitney equation -
4 things
-SA
- solubility in the diffusion layer
-concentration of the drug
-thickness of the diffusion layer
tablet excipients
filler/diluent - bulking agent - lactose
disintegrant - enables the breakdown by rupturing the tablet. -starch
absorption enhancers - modulates -permeability of a membrane - surafcants
Binder - mechanical strength - cellulose
dissolution enhancer- increases solubility - magnesium oxide
glidant- improves flowability of the powder - magnesium stearate
lubricant -ensures ejection from the die - magnesium stearate or stearic acid.
what are 4 drug release
- immediate release - rapid
-extended/prolonged release - releases slowly and constant rate
-pulsatile release - 2 or more pulses
-delayed release - delayed after some time from administration (enteric coat)
what is the enteric coating and when are they used(3) ?
pH sensitive polymers that are insoluble in acid but dissolve in natural or slightly alkaline conditions of the gut.
-drug is inactivated or destroyed by acid in stomach
-drug is irritating to the gastric mucosa
-when bypass from stomach enhances absorption.
what is a capsule
edible packages filled with medicine to produce a unit dose
what is a solution
mixture of 2 or more components that form a single phase that is homogeneous down to the molecular level.
excipients
flavouring agent - palatable
colouring agent - make it attractive
antioxidants - stability
pH adjusters - so site of administration isnt irritated
viscosity enhancer - easy to handle
preservatives - to preserve multidose preparations.
solubility enhancer - maintains solubility of the drug
what is a suspension
solid within a liquid vehicle. does not dissolve
